Laboratory results in ocular viral diseases: implications in clinical-laboratory correlation

To document etiology and predictive value of clinical diagnosis in laboratory confirmed viral diseases.

Reports of culture-positive cases of samples collected from patients presenting from January 1987 - December 2001 were evaluated.

One thousand nine hundred and sixty-four (1964) cultures were submitted during 1987-2001. Twenty-six percent were positive (514). Human herpesvirus 1 was the most frequent agent isolated from all positive culture (56%). Adenovirus was the most common virus isolated from conjunctiva (66%), human herpesvirus 1 from lid and cornea (76%, 88%) and cytomegalovirus from vitreous (27%). Some unusual pathogens were recovered from conjunctiva as cytomegalovirus and from cornea as adenovirus, enterovirus and cytomegalovirus. Recognition of common viral syndromes was human herpesvirus 1 (88%), epidemic keratoconjunctivitis (88%), acute hemorrhagic conjunctivitis (70%) and varicella zoster virus (100%). However, some misdiagnosed cases were observed. Thirteen percent of conjunctivitis thought to be caused by herpes were due to adenovirus, 3.2% to Enterovirus, 3.2% to varicella zoster virus and 3.2% to human cytomegalovirus. Also, 5% of cases with a clinical diagnosis of herpes keratitis were caused by adenovirus and 2.7% by enterovirus. Finally, 4.8% of cases thought to be adenovirus conjunctivitis were herpes conjunctivitis.

Human herpesvirus 1 remains the most frequently isolated virus from ocular sites in general (56%). Nonherpetic corneal isolates were in decreasing order: adenovirus, enterovirus and cytomegalovirus. Clinical and laboratory correlation was less than 90%. The most misdiagnosed cases were herpes conjunctivitis and keratitis, some cases of adenovirus conjunctivitis some cases of acute hemorrhagic conjunctivitis. It is essential that a rapid and specific diagnosis is offered under atypical viral presentation for the institution of specific antiviral therapy and to avoid complications that can be a result of misdiagnosis and inappropriate treatment. Also it is important to do viral testing in order to confirm clinical diagnosis, report emerging infections, resistance and change in the epidemiology.